Device for clamping and holding an elongated workpiece

ABSTRACT

A device for receiving and processing an elongated workpiece that proceeds along a path is disclosed. The device comprises a plurality of clevis-shaped members, each clevis-shaped member being pivotable about a vertical axis and having a pair of spaced apart upwardly extending posts. The clevis-shaped members are spaced apart relative to the path, and the posts of each clevis-shaped member defining therebetween a centered workstation disposed along the path. At least one actuator is provided, with the actuator operatively engaging each of the clevis-shaped members such that the each clevis-shaped member will pivot about its vertical axis. Accordingly, in response to operation of the actuators the posts of each of the clevis-shaped members shift in unison to center and clamp the workpiece at the workstation.

RELATED APPLICATIONS

[0001] This application is a continuation-in-part and claims priorityfrom earlier filed U.S. Application Ser. No. 09/081,223, filed Feb. May19, 1998.

FIELD OF THE INVENTION

[0002] The present invention relates generally to clamping devices, andmore specifically to a device that clamps a workpiece for processing.

BACKGROUND OF THE INVENTION

[0003] Polyvinyl tubing is commonly used for many purposes, including byway of example rather than limitation, fencing, decking, lawn furniture,etc. In such applications, it is often required that the polyvinyltubing be processed in one or more ways. For example, in manyapplications holes or slots must be cut into one or more of thesidewalls in order to accommodate mounting hardware or other associatedcomponents, or to otherwise permit a portion of one piece of tubing tobe inserted into a portion of another piece of tubing. In otherapplications, such as polyvinyl decking systems, it may desirable to cutgrooves into one surface of the tubing in order to create a non-slipsurface.

[0004] The processing of such components often involves the use of adrill or router which is guided by a template or by a computerizedcontrol system. In such a process, the workpiece (e.g., a piece oftubing or some other piece of stock) must be secured in a predeterminedlocation, with the workpiece being aligned and centered. Moreover, inorder to ensure processing efficiencies, the workpiece must be quicklyinserted and clamped prior to processing, and must further be quicklyremoved after processing.

[0005] There exists a continuing need for improved clamping devices.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006]FIG. 1 is a fragmentary view in perspective of a process machinefor processing elongated articles, such as polyvinyl tubing,incorporating a clamping mechanism made pursuant to the teachings of thepresent invention;

[0007]FIG. 2 is an exploded view of the apparatus illustrated in FIG. 1;

[0008]FIG. 3 is a fragmentary top plan view of the apparatus illustratedin FIG. 1 and illustrating a workpiece illustrated being conveyed ontothe device;

[0009]FIG. 4 is a view similar to FIG. 3, but illustrating the workpieceinstalled in the apparatus and with the clamping members engaging theworkpiece to hold the workpiece in place for processing;

[0010]FIG. 5 is a cross-sectional view taken substantially along line5-5 of FIG. 1;

[0011]FIG. 6 is a view similar to FIG. 5, but illustrating the manner inwhich the device can be adjusted to accommodate a workpiece of a smallersize than the workpiece illustrated in FIG. 5;

[0012]FIG. 7 is a fragmentary view in perspective of a clamping deviceassembled in accordance with the teachings of a second preferredembodiment of the invention;

[0013]FIG. 8 is an end elevational view taken along line 8-8 of FIG. 7;

[0014]FIG. 9 is a top plan view of the clamping device illustrated inFIG. 7;

[0015]FIG. 10 is a side elevational view of the device shown in FIGS.7-9;

[0016]FIG. 11 is a fragmentary view in perspective of a clamping deviceassembled in accordance with the teachings of a third preferredembodiment of the invention;

[0017]FIG. 12 is an end elevational view taken along line 12-12 of FIG.11;

[0018]FIG. 13 is a top plan view of the clamping device illustrated inFIG. 11;

[0019]FIG. 14 is a side elevational view of the device shown in FIGS.11-13;

[0020]FIG. 15 is a fragmentary view in perspective of a clamping deviceassembled in accordance with the teachings of a fourth preferredembodiment of the invention;

[0021]FIG. 16 is an end elevational view taken along line 16-16 of FIG.15;

[0022]FIG. 17 is a top plan view of the clamping device illustrated inFIG. 15;

[0023]FIG. 18 is a side elevational view of the device shown in FIGS.15-17;

[0024]FIG. 19 is an enlarged fragmentary cross-sectional view takenalong line 19-19 of FIG. 18;

[0025]FIG. 20 is a fragmentary view in perspective of a clamping deviceassembled in accordance with the teachings of a fifth preferredembodiment of the invention;

[0026]FIG. 21 is an end elevational view taken along line 21-21 of FIG.20;

[0027]FIG. 22 is a top plan view of the clamping device illustrated inFIG. 20; and

[0028]FIG. 23 is a side elevational view of the device shown in FIGS.20-22;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] The following description of the disclosed embodiment is notintended to limit the scope of the invention to the precise form orforms detailed herein. Instead, the following description is intended tobe illustrative of the principles of the invention so that others mayfollow its teachings.

[0030] Referring now to the drawings, a machine 10 for cutting openingsin the side walls of an elongated workpiece 12 (FIG. 3) includes a fixedsupport or table generally indicated by the numeral 14, which includes apair of longitudinal side frame members 16, and a pair of transverselyextending upper end frame members 18 which interconnect the side framemembers 16. Legs 20 extend downwardly from each end of both side framemembers 16. A lower transverse member 22 interconnects the legs 20 oneach end of the machine 10. Levelers 24 extend downwardly from each endof both lower transverse members 22. A pair of elevators 26 areinstalled on each of the lower transverse members 22 and consist of anouter member 28 and an inner member 30 which extends from, and retractsinto, the outer member 28. The inner member 30 extends through thecorresponding upper end frame member 18. The elevators 26 may beoperated manually, such as by a crank, pneumatically, or in any othermanner.

[0031] A conveyor generally indicated by the numeral 32 is supportedalong the center line defined by the side frame members 16 by theelevators 26. The conveyor 32 includes a pair of side frame members 34which extend substantially parallel to the side frame members 16 of thefixed support or table 14. Conveyor 32 further includes transverse endmembers 36 which are secured to the inner members 30 of elevators 26.Accordingly, by operation of the elevators 26, the conveyor 32 may beraised and lowered relative to the fixed support or table 14.Conventional rollers 38 extends between the side members 34 and arejournaled for rotation relative thereto. It will be noted that in thedisclosed embodiment intermittent gaps 39 are provided between sets ofthe rollers 38 in which the spacing between rollers is substantiallygreater than the normal spacing between the rollers 38.

[0032] A clamping and holding mechanism assembled in accordance with afirst preferred embodiment of the invention is generally indicated bythe numeral 40. The clamping and holding mechanism 40 includes a pair oflongitudinally extending, transversely spaced clamping members 42 whichextend generally parallel to the side frame members 16. A shaft 44 ismounted between a pair of extensions 46 extending upwardly from the endframe member 18 on one end of the support or table 14. Glides 48 aremounted on one end of each of the clamping members 42 and are slidablyengaged with the shaft 44, to thereby restrain the clamping members 42to movement transverse to the conveyor 32 and restraining the clampingmembers 42 against longitudinal movement. The clamping members 42 areactuated by camming members generally indicated by the numeral 50.

[0033] As shown in FIG. 2, each of the camming members 50 includes anaxle 52 which is rotatably supported in a corresponding one of a numberof cross members 54 which extend between the side frame members 16intermediate the end frame members 18. A radially extending plate 56 ismounted for rotation with each axle 52 on the end thereof that projectsabove the cross members 54. A crank arm 58 is mounted for rotation withsome of the axles 52 and is mounted on the end thereof extending belowthe cross members 54. Each of the crank arms 58 is operated by apneumatic actuator 60 which extends between each crank arm 58 and abracket 62 mounted on one of the side frame members 16. Alternatively,the actuators 60 may be attached directly to an end of the plate 56. Inorder to reduce the number of actuators 60, one or more tie rods 64 maybe pivotally connected between a corresponding end of adjacent plates56, so that rotation of any of the plates 56 will be transferred torotate all of the other plates 56 in the same direction. Arms 66 arerigidly mounted adjacent opposite ends each of the plates 56 and extendupwardly therefrom. Each of the arms 66 engage a corresponding one ofthe clamping members 42.

[0034] Accordingly, when the pneumatic actuators 60 are operated to turnthe crank arm 58 in the counterclockwise direction (viewed from above),the plates 56 will be rotated in the same direction and, because thearms 66 are rigidly connected to the plates 56 but pivotal and slidablerelative to the clamping members 42, the clamping members 42 will movetransversely toward the center line of the conveyor 32. In the disclosedembodiment, longitudinal movement of the clamping members 42 isprevented by virtue of the glides 48 slidably mounted on the shaft 44.When the pneumatic actuators are operated to rotate the crank arms 58and plates 56 in the clockwise direction, the clamping members 42 arespread apart. One of the clamping members 42 carries a spring loaded pin68 (FIGS. 3 and 4) that is urged outwardly from the inner edge of theclamping member to engage an end of the workpiece 12 as most clearlyillustrated in FIG. 4, to thereby locate the workpiece in apredetermined position relative to the machine 10 when the work piece isprocessed as will hereinafter be explained.

[0035] A router carriage generally indicated by the numeral 70 includesa bridge 72 having opposite ends 74 which are provided with glides 76 toslidably engage a corresponding one of rails 78 which are mounted on theside frame members 16 and extend upwardly therefrom. Accordingly, thebridge 72 may slide along the side frame members 16 between the ends ofthe table or export 12. The height of the bridge is established by anumber of uprights 80 so that transverse portions 82 clear the conveyor32 and the clamping members 42. Shafts 84 extend between correspondingpairs of the uprights 80 substantially parallel to the side framemembers 16. A router support 86 is slidably mounted on the shafts 84 formovement longitudinally along the conveyor 32. The router support 86carries a pair of transversely extending shafts 88 which slidably engagethe router 90 to guide the router for movement transverse to theconveyor 32. Accordingly, by sliding relative to the shafts 84 and 88,the router 90 can be positioned at any point along the upper side of theworkpiece 12 when the workpiece 12 is installed in the machine 10 andengaged by the clamping members 42. The router 90 is guided by aconventional follower arm 92 which traces on the pattern 96 incorporatedwithin a template 94, in a manner well known to those skilled in theart. Necessary electrical connections to the router 90 are made byelectrical wiring extending through a clamp 98 attached to the carriage70.

[0036] In operation, the workpiece 12 is placed upon the rollers 38 fromthe right hand end of the machine 10 (viewing FIGS. 1-4). The workpiece12 is supported by the rollers 38, and the operator may easily push theworkpiece 12 into the machine 10 until the end of the workpiece 12engages the pin 68 to locate the workpiece relative to the machine 10.The height of the conveyor 32 may be adjusted by operation of theelevators 26 to bring the workpiece 12 to the proper height where it maybe engaged by the router 90 and in which the end of the workpiece willengage the spring loaded pin 68. For example, in FIG. 5, a relativelylarge cross section workpiece is being processed, so such that theelevators 26 are used to lower the conveyor 32. In FIG. 6 a smallercross section workpiece is illustrated in which the conveyor 32 has beenraised to properly position the workpiece 12 relative to the router 90.

[0037] After the workpiece 12 has been installed in the machine 10, thepneumatic actuators 60 are operated to rotate the camming members 50.Since the axle 52 of each camming member 50 is located along thecenterline of the machine 10, rotation of the camming members 50 in thecounterclockwise direction (viewed from above) causes the clampingmembers 42 to move towards the center line of the conveyor 32, eachclamping member 42 moving towards the center line from oppositedirections. Accordingly one of the clamping members 42 will engage theside of the workpiece before the other clamping member 42 engages theother side of the workpiece, unless the workpiece is aligned along thecenter line. The work piece will be moved transversely as the clampingmembers 42 close against opposite sides of the workpiece, therebyaligning the center line of the workpiece along the center line of themachine 10.

[0038] Processing of the workpiece using the router 90 may then begin.The carriage 70 is moved manually along the tracks 78 along the template96, which extends along the side of the machine. After the follower arm92 is installed in the pattern 96 defined in the template 94, operationof the router 90 is initiated to cut the desired apertures in theworkpiece 12. Accordingly, the carriage 70 is moved manually along theworkpiece to cut successive apertures or other features into theworkpiece 12. Of course, it is within the scope for the invention to usethe clamping mechanism with more automated types of machines, in whichthe router or equivalent cutting or processing device is indexed bynumerical control along the length of the workpiece. It is alsoobviously within the scope of the invention to provide other types ofprocessing of the workpiece other than by router, and processing ofdifferent types of workpieces, such as shafts, elongated metal parts,etc.

[0039] Referring now to FIGS. 7 through 10, a clamping and holdingdevice assembled in accordance with the teachings of a second embodimentof the invention is shown and is referred to by the reference numeral140. It will be understood that the clamping and holding device 140 maybe suitably mounted to any suitable frame or support, such as, forexample, the table 14 discussed above with respect to the firstembodiment. In the disclosed embodiment, the clamping and holdingmechanism 140 may be mounted to one or more of the cross members 54(shown in fragment in FIGS. 7, 8 and 10) of the table 14. The clampingand holding device 140 includes a pair of elongated clamp rails 142 a,142 b which function to engage the work piece 12 in a manner similar tothat discussed above with respect to the first disclosed embodiment. Itwill be noted that the clamp rails 142 a, 142 b are disposed on oppositesides of a path along which the workpiece 12 proceeds, with the pathbeing indicated in FIG. 7 by the reference character A. The clamp rails142 a, 142 b are engaged by a plurality of clamp members 144 which arespaced apart along the path A.

[0040] Referring now to FIG. 8, each of the clamp members 144 includes apair of uprights 146 a, 146 b, each of which has an upper end 146 cwhich engages an adjacent one of the clamp rails 142 a, 142 b. Each ofthe uprights 146 a, 146 b also includes a lower end 146 d. The lowerends 146 d of the uprights 146 a, 146 b are mounted to a cross member148, and the cross member 148 is mounted to an axle 152. The axle 152 ismounted to the cross member 54 (discussed above with respect to thefirst embodiment and shown in fragment in FIGS. 7, 8 and 10) so as to bepivotable about its longitudinal axis. In the disclosed embodiment, theaxle 152 is pivotably mounted to the cross member 54 by a pair ofjournaled supports 154. A lower end 156 of the axle 152 extends belowthe lower support 154, and a lever arm 158 is mounted to the lower end156 of the axle 152 and extends laterally therefrom. Alternatively, theaxle 152 may be suitably mounted to a single journaled support 154.Further, the lever arm may extend from a central portion or an upperportion of the axle 152. Also, it will be noted when viewing FIG. 7 thatnot all of the clamp members 144 need include a lever arm 158. However,for each of the clamp members 144 including the lever arm 158, anactuator 160 is provided, each of which is connected to one of the leverarms 158 and also to a fixed support (not shown), such as a fixedportion of the table 14. Alternatively, the actuator 160 may beconnected directly the cross member 148. It will be understood that anumber of different mechanisms may be employed to pivot the clampmembers 144, such as, by way of example and not limitation, a gearmechanism or a suitable linkage mechanism. The operation of theactuators 160 is controlled by a controller 161 (illustratedschematically in FIG. 10). It will be understood that the actuators 160(or any of the actuators discussed herein with respect to any of thedisclosed embodiments) may be any suitable commercially availableactuators, such as pneumatic actuators, hydraulic actuators, air overoil actuators, electric linear actuators, servo motors, stepper motors,or any other type of powered actuators.

[0041] Referring now to FIGS. 7 and 9, the upper end 146 c of each ofthe uprights 146 a, 146 b may be pivotably connected to itscorresponding clamp rail 142 a, 142 b, respectively, by a pivot 162. Byvirtue of the pivots 162, in response to rotation of the cross members148 in the clockwise direction caused by the extension of the actuator160, the clamp rail 142 a will move to the left when viewing FIG. 9,while the clamp rail 142 b will move to the right when viewing FIG. 9.It will be understood of course that the clamp rails 142 a and 142 bwill also move inwardly toward a workstation disposed along the path A.When the operation of the actuator 160 is reversed, the clamp rails 142a and 142 b will move in the opposite directions and away from the pathA. As an alternative, the upper ends 146 c of the uprights 146 a and 146b may pivotably and slidably engage their corresponding clamp rails 142a, 142 b. In such an alternative situation, each of the clamp rails 142a and 142 b would be provided with a guide, such as the guides 48 whichengage a transverse shaft 44 in a manner similar to that discussed abovewith respect to the first disclosed embodiment and which arrangement isshown in FIGS. 1, 2 and 3. It will be understood that in such analternative arrangement the guides 48 engaging the shaft 44 will preventlongitudinal movement of the clamp rails 142 a, 142 b, such that theywill move inward and outward in a manner similar to the movement of therails 42 in the first embodiment.

[0042] In operation, the workpiece 12 proceeds along the path Asupported by a suitable conveyor, such as the conveyor 32 discussedabove with respect to the first disclosed embodiment. Once the workpiece12 has reached the desired location, which is typically defined when theleading end of the workpiece 12 comes into contact with the springloaded pin 68 (discussed above with respect to the first disclosedembodiment) or any other suitable stop (not shown), the actuators 160are activated. Viewing FIG. 9, when the actuators 160 are extended, eachof the clamp members 144 will pivot about its respective axle 152 in agenerally clockwise direction when viewed from above. Again, thepivoting action of the clamp members 144 is provided by the actuators160 engaging the lever arm 158 on selected ones of the clamp members144. The rotation of the clamp members 144 causes the clamp rails 142 aand 142 b to move closer to the center line of the path A, such that theinward edges of the clamp rails 142 a, 142 b will come into contact withthe side edges of the workpiece 12, thus centering and clamping theworkpiece 12 at the desired workstation. The processing operations suchas the drilling of holes, the cutting of grooves, or other operations,are then carried out using the router 90 or other required tools in themanner discussed in greater detail above with respect to the firstdisclosed embodiment.

[0043] When the processing of the workpiece 12 is complete, theactuators 160 are retracted, which once again moves the rails 142 a and142 b outwardly and away from the workpiece 12, thus permitting theworkpiece 12 to be conveyed off the machine 10. Another workpiece maythen be processed in a similar manner.

[0044] Referring now to FIGS. 11 through 14, a clamping and holdingdevice assembled in accordance with the teachings of a third embodimentof the invention is shown and is referred to by the reference numeral240. The clamping and holding device 240 may be suitably mounted to anysuitable frame or support, such as the table 14 discussed above withrespect to the first embodiment. The clamping and holding mechanism 240may be mounted to one or more of the cross members 54 (shown in fragmentin FIG. 11) of the table 14. The clamping and holding device 240includes an elongated link arm 242 which interconnects a plurality ofclamp members 244 which are spaced apart along the path A.

[0045] Referring now to FIG. 12, each of the clamp members 244 includesa pair of uprights 246 a, 246 b, each of which has an upper end 246 c.Each of the uprights 246 a, 246 b also includes a lower end 246 d. Thelower ends 246 d of the uprights 246 a, 246 b are mounted to a crossmember 248, and each of the cross member 248 is mounted to an axle 252.The axle 252 is mounted to the cross member 54 so as to be pivotableabout its longitudinal axis. In the disclosed embodiment, the axle 252is pivotably mounted to the cross member 54 by a pair of journaledsupports 254. The link arm 242 is mounted to each of the clamp members244, such that the rotational movement of all of the clamp members 244about their respective axes will be synchronized (i.e., they will allmove in unison). In the disclosed embodiment the link arm 244 is mountedto the cross members 248. Alternatively, the link arm 242 may be mountedto the uprights 246 a or 246 b. A number of actuators 260 are provided,each of which is connected to the link arm 242. Alternatively, theactuators 260 may be mounted to a lever arm (not shown) or othersuitable mechanism engaging the axle 252, or the actuators 260 may bemounted directly to the clamp members 244 in order to rotate the clampmembers 244. The operation of the actuators 260 is controlled by acontroller 261 (illustrated schematically in FIG. 14).

[0046] In operation, the workpiece 12 proceeds along the path Asupported by a suitable conveyor, such as the conveyor 32 discussedabove with respect to the first disclosed embodiment. Once the workpiece12 has reached the desired location, which again may be defined when theleading end of the workpiece 12 comes into contact with the springloaded pin 68 (discussed above with respect to the first disclosedembodiment) or any other suitable stop (not shown), the actuators 260are activated by the controller 261. Viewing FIG. 13, when the actuators260 are extended, each of the clamp members 244 will pivot about itsrespective axle 252 in a generally clockwise direction when viewed fromabove. The pivoting action of the clamp members 244 is synchronized bythe link arm 242. The rotation of the clamp members 244 causes theuprights 246 a, 246 b to move closer to the center line of the path A,such that the inward portions of the uprights 246 a, 246 b will comeinto contact with the side edges of the workpiece 12, thus centering andclamping the workpiece 12 at the desired workstation. Once again, theprocessing operations such as the drilling of holes, the cutting ofgrooves, or other operations, are then carried out using the router 90or other required tools in the manner discussed in greater detail abovewith respect to the first disclosed embodiment.

[0047] Referring now to FIGS. 15 through 19, a clamping and holdingdevice assembled in accordance with the teachings of a fourth embodimentof the invention is shown and is referred to by the reference numeral340. The clamping and holding device 340 may be suitably mounted to anysuitable frame or support, such as the table 14 discussed above withrespect to the first embodiment. The clamping and holding mechanism 340may be mounted to one or more of the cross members 54 (shown in fragmentin FIG. 15) of the table 14. The clamping and holding device 340includes a plurality of counter-pivoting clamp members 344 and aplurality of counter-pivoting clamp members 345, all of which are spacedapart along the path A.

[0048] Each of the clamp members 344 includes a first clamp 344 a and asecond clamp 344 b, which counter-rotate relative to each other about acommon pivot axis 347. The clamp 344 a includes a pair of uprights 344 cmounted to a common cross member 348 a, while the clamp 344 b includes apair of uprights 344 d mounted to a common cross member 348 b. Theuprights 344 d are both pivotably mounted to the cross member 348 b, andare both operatively connected to a drive motor 349 by a drive belt 351.

[0049] Referring now to FIG. 19, the clamp 344 a is mounted to a hollowpivot axle 352 which is rotatably mounted within a pair of journaledsupports 354 s. The clamp 344 b is mounted to a pivot axle 355 which isrotatably received within the hollow pivot axle 352. Each of the axles352 a and 352 b includes a lever 358 a, 358 b, respectively, whichextends outwardly. An actuator 360 a engages the lever 358 a, while anactuator 360 b engages the lever 358 b. The clamps 344 are similar inall respects to the clamps 345, except for the omission of the rotatableuprights and the motors 349.

[0050] In operation, the workpiece 12 proceeds along the path A. Theworkpiece may supported by a suitable conveyor, such as the conveyor 32discussed above with respect to the first disclosed embodiment. However,forward motion of the workpiece 12 along the path A is caused byrotation of the uprights 344 d in response to operation of the motors349. Accordingly, the conveyor 32 need not include a separate drivingmechanism. Still further, the conveyor 32 may be dispensed with in itsentirety, with the functions of supporting the workpiece 12 beingperformed solely by the clamps 344 a and 344 b, and the function ofmoving the workpiece 12 along the path A being performed solely by therotating uprights 344 d on the clamps 344 b.

[0051] Once the workpiece 12 has reached the desired location, whichagain may be defined when the leading end of the workpiece 12 comes intocontact with the spring loaded pin 68 (discussed above with respect tothe first disclosed embodiment) or any other suitable stop (not shown),the actuators 360 a and 360 b are activated. Viewing FIG. 17, operationof the actuators 360 a and 360 b will cause the uprights 344 c of theclamp 344 a and the uprights 344 d of the clamp 344 b to move inwardlyin unison toward the path A, thus engaging, centering and holding theworkpiece 12 at the work station. The counter-rotating pivoting actionof the clamps 344 a and 344 b is synchronized by synchronizing theoperation of the actuators 360 a and 360 b using any suitable controlsystem (not shown) which control system would be within the ability ofone skilled in the art. Once again, the processing operations such asthe drilling of holes, the cutting of grooves, or other operations, arethen carried out using the router 90 or other required tools in themanner discussed in greater detail above with respect to the previousembodiments.

[0052] Referring now to FIGS. 20 through 23, the clamping and holdingdevice 340 is shown in which the clamp members 344 described above areeliminated, and instead only the clamp members 345 are employed. It willbe understood that in such a situation the conveyor 32 discussed abovewith respect to the first disclosed embodiment, or any other suitableconveyor, must still be employed. In all other respects, the alternativearrangement of FIGS. 20 through 23 is essentially the same as thatoutlined above with respect to FIGS. 15 through 19.

[0053] Those skilled in the art will appreciate that, although theteachings of the invention have been illustrated in connection withcertain embodiments, there is no intent to limit the invention to suchembodiments. On the contrary, the intention of this application is tocover all modifications and embodiments fairly falling within the scopeof the appended claims either literally or under the doctrine ofequivalents.

What is claimed:
 1. A device for clamping an elongated workpiece for processing, the workpiece having a longitudinal axis, the device comprising: a conveyor arranged to convey the workpiece along a central path to a workstation, the central path being generally parallel to the longitudinal axis of the workpiece; a pair of elongated clamping members oriented generally parallel to and straddling the path; a plurality of clevis-shaped members, the clevis-shaped members being spaced apart along the path, each clevis-shaped member having a pair of uprights, each of the uprights pivotally connected to one of the elongated clamping members such that the elongated clamping members are supported exclusively by the clevis-shaped members; and at least one actuator operatively connected to each of the clevis-shaped members; whereby in response to operation of the actuators the clamping members are shiftable in unison between a first position in which each clamping member is disposed away from the path and a second position in which each of the clamping members is shifted toward the path, thereby clamping and centering the workpiece at the workstation.
 2. The device of claim 1, wherein each of the clevis-shaped members includes a vertically oriented axle having an axis perpendicular to and intersecting the central path.
 3. A device for receiving and processing an elongated workpiece that proceeds along a path, the device comprising: a plurality of clevis-shaped members, each clevis-shaped member pivotable about a vertical axis and having a pair of spaced apart upwardly extending posts, the clevis-shaped members being spaced apart relative to the path, the posts of each clevis-shaped member defining therebetween a centered workstation disposed along the path; at least one actuator, the actuator operatively engaging each of the clevis-shaped members for pivoting each clevis-shaped member about its vertical axis; whereby in response to operation of the actuators the posts of each of the clevis-shaped members shift in unison to center and clamp the workpiece at the workstation.
 4. The device of claim 3, wherein at least one of the clevis-shaped members is adapted to convey the workpiece along the path.
 5. The device of claim 3, wherein at least one of the clevis-shaped members includes a pair of vertically oriented rollers straddling the path, the rollers being arranged to convey the workpiece along the path.
 6. The device of claim 4, wherein the rollers of the at least one clevis-shaped member are pivotal about a vertical axis, and including a motor mounted adjacent to and engaging each of the rollers.
 7. The device of claim 3, including a controller arranged to control the operation of the actuator.
 8. The device of claim 6, including a controller arranged to control the operation of the actuator and the operation of the motors.
 9. The device of claim 3, including a conveyor for conveying the workpiece along the path, the conveyor being vertically adjustable for raising and lowering the workpiece relative the clevis-shaped clamping members.
 10. A device for clamping an elongated workpiece for processing, the workpiece having a longitudinal axis, the device comprising: a conveyor arranged to convey the workpiece a path to a workstation, the path being generally parallel to the longitudinal axis of the workpiece; a plurality of clamps disposed along the path, each of the clamps including a pair of counter-rotating members pivotable about a common vertically oriented axis, each of the counter-rotating members having a pair of upwardly extending posts straddling the path; a first actuator operatively engaging a first one of the counter rotating members of each clamp for rotating the first counter rotating member in a first direction; a second actuator operatively engaging a second one of the counter rotating members of each clamp for rotating the second counter rotating member in a second direction opposite to the first direction; whereby in response to operation of the actuators the posts of all of the clamps shift in unison and cooperate to center and clamp the workpiece at the workstation.
 11. The device of claim 10, wherein the first counter rotating member includes a first shaft pivotable about the axis, the first shaft being hollow, and the second counter rotating member includes a second shaft pivotally disposed within the first shaft.
 12. The device of claim 11, wherein each of the first and second shafts includes a laterally extending lever, the first actuator engaging the laterally extending lever of the first shaft and the second actuator engaging the laterally extending lever of the second shaft.
 13. The device of claim 10, including a controller arranged to control the operation of the first and second actuators.
 14. A device for clamping an elongated workpiece for processing, the workpiece having a longitudinal axis, the device comprising: a conveyor arranged to convey the workpiece a path to a workstation, the path being generally parallel to the longitudinal axis of the workpiece; a plurality of clamps disposed along the path, each of the clamps including a pair of members rotatable in unison from a retracted position to a clamping position, the members straddling the path and centering the workpiece when in the clamping position; actuation means operatively engaging the pair of members for each of the clamps, the actuation means for shifting each of the pair of members between the retracted position and the clamping position; whereby in response to operation of the actuation means the pair of members for all of the clamps shift in unison to center and clamp the workpiece at a workstation disposed along the path.
 15. A device for clamping an elongated workpiece for processing, the workpiece having a longitudinal axis, the device comprising: a plurality of clamps disposed along a path, each of the clamps including a pair of shiftable arms adapted to engage the workpiece, the clamps being shiftable between a retracted position in which the arms are disposed away from a workstation disposed along the path and a clamp position in which the arms clamp and center the workpiece at the workstation, the arms straddling the path when in the clamp position; and actuation means engaging the clamps for shifting the clamps in unison between the retracted position and the clamp position.
 16. A device for clamping an elongated workpiece for processing, the workpiece having a longitudinal axis, the device comprising: a plurality of counter-rotating clamps disposed along the path, the clamps being shiftable between a retracted position and a clamp position, each of the clamps being adapted to engage the workpiece when the clamps are in the clamp position; a plurality of conveying rollers carried by at least some of the clamps, the conveying rollers being positioned to engage the workpiece and to convey the workpiece along the path to the workstation, the path being generally parallel to the longitudinal axis of the workpiece; and a plurality of actuators operatively engaging the clamps, the actuators being arranged to shift each of the clamps in unison to the clamp position; thereby centering and clamping the workpiece at the workstation. 